/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.nifi.attribute.expression.language.evaluation.functions;

import org.apache.nifi.attribute.expression.language.EvaluationContext;
import org.apache.nifi.attribute.expression.language.evaluation.Evaluator;
import org.apache.nifi.attribute.expression.language.evaluation.QueryResult;
import org.apache.nifi.attribute.expression.language.evaluation.StringEvaluator;
import org.apache.nifi.attribute.expression.language.evaluation.StringQueryResult;
import org.apache.nifi.uuid5.Uuid5Util;

// This is based on an unreleased implementation in Apache Commons Id. See http://svn.apache.org/repos/asf/commons/sandbox/id/trunk/src/java/org/apache/commons/id/uuid/UUID.java
public class Uuid5Evaluator extends StringEvaluator {

    private final Evaluator<String> subject;
    private final Evaluator<String> namespace;

    public Uuid5Evaluator(final Evaluator<String> subject, final Evaluator<String> namespace) {
        this.subject = subject;
        this.namespace = namespace;
    }

    @Override
    public QueryResult<String> evaluate(final EvaluationContext evaluationContext) {
      final String subjectValue = subject.evaluate(evaluationContext).getValue();
      if (subjectValue == null) {
          return new StringQueryResult(null);
      }
      final String nsValue = namespace.evaluate(evaluationContext).getValue();

      String uuid = Uuid5Util.fromString(subjectValue, nsValue);

      return new StringQueryResult(uuid);
    }

    @Override
    public Evaluator<?> getSubjectEvaluator() {
        return subject;
    }
}
